before text
\begin{equation}%
	x^2+y^2=4%
\end{equation} and
\begin{equation}%
	\Re{z}=4%
\end{equation}

\begin{equation}
	r^2+\phi^2 = \theta^2
\end{equation}
and also
\begin{equation}%
	x^2
\end{equation} and some inline math: $f(x)$
